Description
Description
Editorial
Editorial
Solutions
Solutions
Submissions
Submissions
Hard

You are given 3 positive integers num_zeros, num_ones, and limit.

A arr is called stable if:

  • The number of occurrences of 0 in arr is exactly num_zeros.
  • The number of occurrences of 1 in arr is exactly num_ones.
  • Each of arr with a size greater than limit must contain at least one occurrence of both 0 and 1.

Return an integer denoting the total number of stable binary arrays.

Since the answer may be very large, return it modulo 109 + 7.

 

Example 1:

Input: zero = 1, one = 1, limit = 2

Output: 2

Explanation:

The two possible stable binary arrays are [1,0] and [0,1].

Example 2:

Input: zero = 1, one = 2, limit = 1

Output: 1

Explanation:

The only possible stable binary array is [1,0,1].

Example 3:

Input: zero = 3, one = 3, limit = 2

Output: 14

Explanation:

All the possible stable binary arrays are [0,0,1,0,1,1], [0,0,1,1,0,1], [0,1,0,0,1,1], [0,1,0,1,0,1], [0,1,0,1,1,0], [0,1,1,0,0,1], [0,1,1,0,1,0], [1,0,0,1,0,1], [1,0,0,1,1,0], [1,0,1,0,0,1], [1,0,1,0,1,0], [1,0,1,1,0,0], [1,1,0,0,1,0], and [1,1,0,1,0,0].

 

Constraints:

  • 1 <= zero, one, limit <= 1000
 
Code
Code
Testcase
Testcase
Test Result
Test Result